Cystic Fibrosis (CF) is caused by a defect in a single gene within the DNA that codes' for a protein called the cystic fibrosis transmembrane conductance regulator (CFTR). This protein acts as a channel to allow salt to get across (trans-), cell membranes; i.e., to conduct sodium and chloride in and out of the cell. The CFTR protein also regulates the function of other membrane salt channels, and so a defect in this gene can have a large impact on the salt concentration in body fluids. Fluids made in a variety of organs are affected, including the lung, pancreas, liver, and sexual organs, but pathology of the airways within the lung is responsible for most of the life threatening problems in CF patients (>90%). Problems with the salt concentration in airway fluids, and abnormalities in protein processing, as well as cytokine production, lead to an increased frequency, duration, and severity of lung infections. The body's own defending immune cells try to eliminate these infections, but in the long term end up secondarily damaging the surrounding lung tissue. This results in severe progressive destruction of the lungs, which the body tries to heal by scarring (fibrosis). This self-destructive process ends up leaving hardened, scarred non-functional lung tissue that contains fluid filled sacs (cysts).
There is currently no cure for CF and thus there is a need in the art to provide a treatment for CF that may slow or even stop the progression of the disease in children before their lungs become severely damaged.